Ex vivo lung perfusion allows successful transplantation of donor lungs from hanging victims

Transplantation of Organs From DCD and DBD Donors Who Died After Ligature Asphyxiation

BACKGROUND

The United Kingdom transplant registry data demonstrated similar transplant outcomes for recipients of kidneys from donors who died following ligature asphyxiation and those who received organs from donors dying from other causes. The impact that this donor cause of death has on the outcomes of other solid organ transplant recipients remains uncertain.

METHODS

The United Kingdom transplant registry analysis was undertaken to determine transplant outcomes in recipients of lungs, hearts, livers' and pancreases from donors who died following ligature asphyxiation.

RESULTS

Between January 01, 2003, and December 31, 2016, 2.7% (n = 521) of all potential United Kingdom donors died following ligature asphyxiation (mostly suicide by hanging). Of these, 416 (79.9%; 197 donation after brain stem death and 219 donation after circulatory death [DCD]) donated an organ for transplantation. These donors provided organs for 574 transplants (66 lung transplants, 75 heart transplants, 279 liver transplants, and 154 pancreas transplants). Patient and graft survival were similar for recipients of both donation after brain stem death and DCD hearts, livers, and pancreases from donors who died following ligature asphyxiation. Unadjusted graft and patient survival were significantly worse for recipients of lungs from DCD donors who died following ligature asphyxiation. This detrimental effect persisted after propensity score matching.

CONCLUSIONS

Livers, hearts, and pancreases from donors who die following ligature asphyxiation suffer an additional warm ischemic insult, but this does not negatively impact transplant outcomes. Outcomes for recipients of DCD lungs appear to be significantly worse.

Donor quality assessment and size match in lung transplantation

Careful donor quality assessment and size match can impact long-term survival in lung transplantation. With this article, we review the conceptual and practical aspects of the preoperative donor lung quality assessment and size matching.

In lung transplantation, are pulmonary grafts from donors deceased from hanging as suitable as grafts from donors deceased from other causes?

A best evidence topic was constructed according to a structured protocol. The question addressed was whether pulmonary grafts from donors deceased from hanging offer the same benefit as grafts from donors deceased from other causes in lung transplantation. Of the 17 papers found, 4 provided the best evidence to answer the question. The authors, date, journal, country of publication, study type, group studied, relevant outcomes and results of these papers are tabulated. One study reported a large cohort of donors and analysed the outcomes by cause of death, reporting no differences in survival. The remaining 3 papers analysed observational studies on the outcomes of lung transplantation using pulmonary grafts from donors deceased from hanging, compared with donors deceased from other causes. No differences in the rates of post-transplantation pulmonary graft dysfunction and long-term overall survival were reported. Although the cohort of donors deceased from hanging is small, we conclude that these donors are an important contribution to the donor pool. Ex vivo lung perfusion may have a role in assessing graft viability in this scenario.

Hanging donor lungs give good short-, mid- and long-term results in lung transplantation

BACKGROUND

Hanging donors are considered as marginal donors and frequently unsuitable for lung transplantation. However, there is no evidence of higher lung transplantation (LTx) morbidity-mortality with lungs providing by hanging donor.

METHODS

Between January 2010 and July 2015, we performed a retrospective study at Foch hospital. We aimed to assess whether hanging donor grafts are suitable for lung transplantation.

RESULTS

A total of 299 LTx were performed. Subjects were allocated to a hanging group (HG) (n = 20) and a control group (CG) (n = 279). Donor and recipient characteristics did not differ. Primary graft dysfunction (PGD) at 72 hours was comparable in both groups (P = .75). The median duration of postoperative mechanical ventilation (1 [range, 0-84] vs 1 [range, 0-410] day, P = .35), the hospital length of stay (31 days [20-84] vs 32 days [12-435], P = .36) did not differ between the two groups. No statistically significant difference was found in 1-year and 5-year survival between the HG (83% and 78%) and the CG (86% and 75%), P = .85.

CONCLUSION

We believe that hanging donors should be considered as conventional donors with particular caution in the final evaluation of the graft and in perioperative management.

Proposed safe apnea test using positive end-expiratory pressure valve and short-term blood gas analysis: Observational study

The apnea test is an essential examination for the determination of brain death; however, hypotension, hypoxemia, and other complications during the apnea test can affect the stability of brain-dead patients, as well as organ function for recipients. Therefore, it is necessary to establish standard guidelines for apnea testing.The modified apnea test (MAT) comprises delivery of 100% oxygen through the endotracheal tube connected to manual resuscitator (Ambu bag) with the positive end-expiratory pressure (PEEP) valve after disconnection of the mechanical ventilator for maintenance of PEEP. Forty-nine instances of the conventional apnea test (CAT) were performed in 25 brain-dead patients; 77 instances of the MAT were performed in 39 brain-dead patients.The mean duration of the apnea test was 3.5 ± 1.4 minutes in the CAT group and 3.0 ± 1.2 minutes in the MAT group. There were no significant changes in PaCO2, PaO2, or pH between the CAT and MAT groups (P = .341, .593, and .503, respectively). In overweight patients (body mass index ≥ 23 kg/m), MAT prevented dramatic reductions in PaO2 and SaO2 (P < .05 for both). In the patients who had hypoxic brain injury due to hanging, differences in PaO2 and SaO2 in the MAT group were significantly smaller than in the CAT group (P < .05).Although MAT, which was invented to maintain PEEP, was not efficient for all brain-dead patients, it could be helpful in selected patient groups, such as overweight patients or those who had hypoxic injury due to hanging. And clinicians should consider short-term apnea test to avoid unnecessarily prolonged hypoxemia.

Lung transplantation after ex vivo lung perfusion in two Scandinavian centres

OBJECTIVES

We reviewed our combined clinical outcome in patients who underwent lung transplantation after ex vivo lung perfusion (EVLP) and compared it to the contemporary control group.

METHODS

At 2 Scandinavian centres, lungs from brain-dead donors, not accepted for donation but with potential for improvement, were subjected to EVLP (n = 61) and were transplanted if predefined criteria were met. Transplantation outcome was compared with that of the contemporary control group consisting of patients (n = 271) who were transplanted with conventional donor lungs.

RESULTS

Fifty-four recipients from the regular waiting list underwent transplantation with lungs subjected to EVLP (1 bilateral lobar, 7 single and 46 double). In the EVLP and control groups, arterial oxygen tension/inspired oxygen fraction ratio at arrival in the intensive care unit (ICU) was 30 ± 14 kPa compared to 36 ± 14 (P = 0.005); median time to extubation was 18 h (range 2-912) compared to 7 (range 0-2280) (P = 0.002); median ICU length of stay was 4 days (range 2-65) compared to 3 days (range 1-156) (P = 0.002); Percentage of expected forced expiratory volume at 1s (FEV1.0%) at 1 year was 75 ± 29 compared to 81 ± 26 (P = 0.18); and the 1-year survival rate was 87% [confidence interval (CI) 82-92%] compared to 83% (CI 81-85), respectively. Follow-up to a maximum of 5 years did not show any significant difference in survival between groups (log rank, P = 0.63).

CONCLUSIONS

Patients transplanted with lungs after EVLP showed outcomes comparable to patients who received conventional organs at medium-term follow-up. Although early outcome immediately after transplantation showed worse lung function in the EVLP group, no differences were observed at a later stage, and we consider EVLP to be a safe method for increasing the number of transplantable organs.

Suicidal hanging donors for lung transplantation: Is this chapter still closed? Midterm experience from a single center in United Kingdom

In the context of limited donor pool in cardiothoracic transplantation, utilization of organs from high risk donors, such as suicidal hanging donors, while ensuring safety, is under consideration. We sought to evaluate the outcomes of lung transplantations (LTx) that use organs from this group.Between January 2011 and December 2015, 265 LTx were performed at our center. Twenty-two recipients received lungs from donors after suicidal hanging (group 1). The remaining 243 transplantations were used as a control (group 2). Analysis of recipient and donor characteristics as well as outcomes was performed.No statistically significant difference was found in the donor characteristics between analyzed groups, except for higher incidence of cardiac arrest, younger age and smoking history of hanging donors (P < .001, P = .022 and P = .0042, respectively). Recipient preoperative and perioperative characteristics were comparable. Postoperatively in group 1 there was a higher incidence of extracorporeal life support (27.3 vs 9.1%, P = .019). There were no significant differences in chronic lung allograft dysfunction-free survival between group 1 and 2: 92.3 vs 94% at 1 year and 65.9 vs 75.5% at 3 years (P = .99). The estimated cumulative survival rate was also similar between groups: 68.2 vs 83.2% at 1 year and 68.2% versus 72% at 3 years (P = .3758).Hanging as a donor cause of death is not associated with poor mid-term survival or chronic lung allograft dysfunction following transplantation. These results encourage assessment of lungs from hanging donors, and their consideration for transplantation.

Comparison of two strategies for ex vivo lung perfusion

BACKGROUND

Two clinically used strategies for ex vivo lung perfusion (EVLP) were compared in a porcine model with respect to lung function, metabolism, inflammatory response, oxidative stress, and cell viability.

METHODS

Porcine lungs (n = 20) were preserved, harvested, and kept cooled for 2 hours. After randomization, EVLP was performed using a cellular perfusate and open left atrium (COA group) or an acellular perfusate and a closed left atrium (ACA group). Oxygenation (partial pressure of arterial oxygen/fraction of inspired oxygen), compliance, dead space, weight, and perfusate oncotic pressure were registered before and after a 4-hour period of reconditioning. Lung tissue samples were collected before and after EVLP for quantitative polymerase chain reaction analysis of gene expression for inflammatory markers, measurement of tissue hypoxia (hypoxia inducible factor-1α) and oxidative stress (ascorbyl radical), and viability (trypan blue staining) and lung histopathology.

RESULTS

In 3 of 10 lungs undergoing EVLP in the ACA group, EVLP was terminated prematurely because of severe lung edema and inability to perfuse the lungs. There were no significant differences in changes of lung oxygenation or pulmonary vascular resistance between groups. Compliance decreased and lung weights increased in both groups, but more in the ACA group (p = 0.083 and p = 0.065, respectively). There was no obvious difference in gene expression for hypoxia inducible factor-1α, inflammatory markers, free radicals, or lung injury between groups.

CONCLUSIONS

Lung edema formation and decreased lung compliance occurs with both EVLP techniques but were more pronounced in the ACA group. Otherwise, there were no differences in lung function, inflammatory response, ischemia/reperfusion injury, or histopathologic changes between the EVLP techniques.

Ex vivo lung perfusion

Lung transplantation is an established life-saving therapy for patients with end-stage lung disease. Unfortunately, greater success in lung transplantation is hindered by a shortage of lung donors and the relatively poor early-, mid-, and long-term outcomes associated with severe primary graft dysfunction. Ex vivo lung perfusion has emerged as a modern preservation technique that allows for a more accurate lung assessment and improvement in lung quality. This review outlines the: (i) rationale behind the method; (ii) techniques and protocols; (iii) Toronto ex vivo lung perfusion method; (iv) devices available; and (v) clinical experience worldwide. We also highlight the potential of ex vivo lung perfusion in leading a new era of lung preservation.